Hydrogel-forming system with hydrophobic and hydrophilic components

Abstract

A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide (e.g., dextran) containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom.

What is claimed is:  
     
       1. A hydrogel forming system which comprises hydrophobic and hydrophilic components (A) and (B) which are convertible into a one phase crosslinked network structure by free radical polymerization, where the hydrophobic and hydrophilic components constitute different compounds from one another, the hydrophobic component (A) being a hydrophobic macromer with unsaturated group terminated ends, and the hydrophilic component (B) being a hydrophilic polymer which is a polysaccharide containing hydroxy groups which are reacted with unsaturated group introducing compound, the unsaturated group introducing compound being selected from the group consisting of acryloyl chloride, methacryloyl chloride, acrylic acid, methacrylic acid and isocyanate having unsaturated group at one end of the molecule, the hydrogel-forming system comprising from 0.01 to 99.00% by weight of (A) and from 99.99 to 0.01% of (B), with the total of the percentages of (A) and (B) being 100%. 
     
     
       2. Hydrogel formed by the free radical polymerization of the hydrogel-forming system of  claim 1  which has a three dimensional crosslinked polymer network structure containing hydrophobic and hydrophilic components. 
     
     
       3. The hydrogel of  claim 2  where the hydrophobic macromer is made from aliphatic polyester starting material. 
     
     
       4. The hydrogel of  claim 2  where the hydrophobic macromer is made from poly (lactic acid) starting material.